Invincibility depends on one's self; the enemy's vulnerability on him.

Let your plans be dark and impenetrable as night.

If this is long delayed, weapons are blunted and morale depressed.

Know the enemy and know yourself.

The general who wins a battle makes many calculations in his temple ere the battle is fought. The general who loses a battle makes but few calculations beforehand. Thus do many calculations lead to victory, and few calculations to defeat: how much more no calculation at all! It is by attention to this point that I can foresee who is likely to win or lose.

In executing an Artful Strategy: When ten times greater, surround them; When five times greater, attack them; When two times greater, scatter them. If the opponent is ready to challenge: When fewer in number, be ready to evade them; When unequal to the match, be ready to avoid them. Even when the smaller opponents have a strong position, the larger opponent will capture them.

The height of strategy, is to attack your opponent's strategy.